1. Field of the Invention
The present invention relates generally to an improved tape drive system and in particular to a method and an apparatus for handling data storage media in the tape drive system. Still more particularly, the present invention provides a method and an apparatus for handling the data storage media, in the form of magnetic tape, by utilizing an intermediate tape leader.
2. Description of the Related Art
Magnetic recording tape is commonly used to store digital data because magnetic recording tape is inexpensive and provides significant data storage capacity per unit volume. Consequently, magnetic recording tape remains an active component in many business operations, especially where large amounts of data must be backed-up for archival purposes. Magnetic recording tape may be housed in a tape cartridge or cassette, which protects the magnetic recording tape from damage.
Data may be read from, or written to, the magnetic recording tape by inserting the tape cartridge, which contains the magnetic recording tape, into a tape drive. The tape drive passes the magnetic recording tape across a read/write head contained within the tape drive. A tape cartridge generally includes either one or two tape reels. A tape reel is used to wind the magnetic recording tape around the tape reel in layers for storage.
A tape cartridge containing two tape reels commonly retains the magnetic tape within the tape cartridge during normal operation. However, a tape cartridge containing a single tape reel requires that the magnetic tape be withdrawn from the tape cartridge for use. The single reel tape cartridge requires a threading mechanism to draw the magnetic recording tape from the tape cartridge in order to place the magnetic recording tape in proximity to the read/write head. The threading mechanism draws the magnetic recording tape from the tape cartridge reel, threads the magnetic recording tape along a tape path, and loads the magnetic recording tape onto a take up reel.
One type of threading mechanism presently used is a two-leader threading mechanism. A two-leader threading mechanism utilizes a cartridge reel tape leader and a drive reel leader. A tape leader is a length of unrecorded tape, or other similar material, used to thread magnetic recording tape into a tape drive. The cartridge reel tape leader is connected at the free end of the magnetic tape and the drive reel leader is connected to the tape drive take-up reel. The tape drive buckles the cartridge reel tape leader and the drive reel leader together by using a leader buckling mechanism. After the leader buckling mechanism buckles the cartridge reel tape leader to the drive reel leader, a tape drive motor is used to wind the drive reel leader onto the tape drive take-up reel. By winding the buckled drive reel leader onto the tape drive take-up reel, the cartridge reel tape leader is threaded through the tape drive's tape path pulling the magnetic tape from the tape cartridge.
Currently, the magnetic recording tape, which is attached to the cartridge reel tape leader, is much more fragile and is very thin in comparison to the cartridge reel tape leader. Pulling the cartridge reel tape leader and the magnetic recording tape through the tape path guide components and across the read/write head protect pins may create edge damage to the magnetic recording tape near the magnetic recording tape/cartridge reel tape leader interface. In addition, the height differential at the magnetic recording tape/cartridge reel tape leader interface may cause impressions extending into the tape pack, which may reduce magnetic recording tape performance. Further, separation of the magnetic recording tape and the cartridge reel tape leader may occur during loading and unloading operations due to the increased stress created by the height differential at the magnetic recording tape/cartridge reel tape leader interface.
Therefore, it would be advantageous to have an improved method and apparatus for handling magnetic recording tape during threading and unthreading of the magnetic recording tape in a tape drive system by utilizing an intermediate tape leader.